In the medical field, in order to treat or rehabilitate a patient who suffers from certain diseases, manual skills are used in the related art, in which various medical members delivered into a biological lumen (for example, a lumen in a living body such as a blood vessel, urethra, ureter, esophagus, airway, bowel, nasal cavity, paranasal sinus, and the like) are caused to indwell in a treatment target site such as a stenosed site or the like. As an example of this treatment, a stent indwelling operation in percutaneous coronary intervention (PCI) is known.
According to the PCI, a stent is mounted on an outer surface of a balloon of a balloon catheter. The balloon is advanced along a guidewire so as to reach a treatment target site inside a blood vessel. Thereafter, the stent is detached from the balloon, and is caused to indwell in the treatment target site. For example, if a medical member is mounted on the balloon instead of the stent, a medical member can be delivered to a desired treatment target site in various biological organs in the same sequence as that of the stent indwelling operation in the related art. In addition, for example, even when the medical member is intended to indwell in a lumen such as a urethra, if a urethral dilating balloon catheter disclosed in Japanese Patent Application No. 8-526731 is diverted to other purposes, the medical member can be delivered to the desired site inside the urethra in the same sequence as that in the PCI.
When the balloon catheter in the related art is used, the balloon is positioned at the treatment target site by using an x-ray contrast marker or the like which is disposed in the balloon. However, it is not easy to arrange indwelling work in such a way that the balloon is positioned at the treatment target site by using the x-ray contrast marker and then the medical member is accurately positioned at the treatment target site. Consequently, it takes a lot of effort to carry out the indwelling work. In addition, after the medical member is arranged at the treatment target site, the balloon is dilated, and the medical member is pressed against the treatment target site. In this manner, the medical member can be prevented from being misaligned. However, if the balloon is not properly positioned at the treatment target site, uneven pressure is inevitably applied to each portion of the treatment target site. Thus, a sufficient holding force (fixing force) is not allowed to act thereon. As a result, the medical member is likely to be misaligned.